System and method for simultaneously offering layer-2 multicast switching and layer-3 multicast routing

Abstract

Provides is a method for processing a multicast packet received in a system for simultaneously providing virtual interface-based layer-2 multicast switching and layer-3 multicast routing. When a destination MAC address of a received Ethernet frame is a multicast MAC address, a VLAN-based layer-2 multicast switching function is performed. When a destination IP address of a received Ethernet frame is a multicast IP address, a virtual interface-based layer-3 multicast routing function is simultaneously performed within the same system.

1. A system for simultaneously providing layer-2 multicast switching and layer-3 multicast routing, wherein a VLAN (virtual local area network)-based layer-2 switch performs a virtual interface-based layer-3 routing function, the system comprising:
 a physical interface for receiving an Ethernet frame; 
 a VLAN defined on the physical interface, for performing a layer-2 multicast switching function on the received Ethernet frame through the same LAN according to a destination MAC address of the received Ethernet frame; 
 a virtual interface for interfacing between the VLAN and a layer-3 router; and 
 a virtual router for mapping a VLAN ID (identifier) of the VLAN to the virtual interface to perform a virtual interface-based layer-3 multicast routing function at the VLAN-based layer-2 switch on the received Ethernet frame according to a destination IP address of the received Ethernet frame, 
 wherein the VLAN ID of the received Ethernet frame is maintained for the layer-2 multicast switching function and the VLAN ID of the received Ethernet frame is changed into a VLAN ID mapped to the virtual interface for the layer-3 multicast routing function. 
 
     
     
       2. The system of  claim 1 , wherein, when the destination MAC (media access control) address of the received Ethernet frame is a multicast MAC address, the VLAN performs the layer-2 multicast switching function. 
     
     
       3. The system of  claim 1 , wherein, when the destination IP address of the received Ethernet frame is a multicast IP address, the virtual router performs the layer-3 multicast routing function. 
     
     
       4. A method for simultaneously providing layer-2 multicast switching and layer-3 multicast routing, wherein a VLAN-based layer-2 switch performs a virtual interface-based layer-3 routing function, the method comprising:
 receiving an Ethernet frame through a physical interface; 
 judging whether a destination MAC address of the received Ethernet frame is a multicast MAC address, copying the same packet when the destination MAC address of the received Ethernet frame is the multicast MAC address as a result of the judgment, and performing a VLAN-based layer-2 multicast switching function; and 
 judging whether a destination IP address of the received Ethernet frame is a multicast IP address, and when the destination IP address of the received Ethernet frame is the multicast IP address as a result of the judgment, performing a virtual interface-based layer-3 multicast routing function at the VLAN-based layer-2 switch, 
 wherein the received Ethernet frame has a VLAN ID (identifier), and the VLAN ID of the received Ethernet frame is maintained for the layer-2 multicast switching function and the VLAN ID of the received Ethernet frame is changed into a VLAN ID mapped to the virtual interface for the layer-3 multicast routing function. 
 
     
     
       5. The method of  claim 4 , wherein performing the VLAN-based layer-2 multicast switching function comprises:
 when the destination MAC address of the received Ethernet frame is the multicast MAC address, judging whether the destination MAC address of the received Ethernet frame is a broadcast MAC address; and 
 when the destination MAC address of the received Ethernet frame is the broadcast MAC address as a result of the judgment, performing a VLAN-based layer-2 broadcast switching function. 
 
     
     
       6. The method of  claim 5 , further comprising, when the destination MAC address of the received Ethernet frame is the broadcast MAC address as a result of the judgment:
 judging whether the destination IP address of the received Ethernet frame is a broadcast IP address; and 
 when the destination IP address of the received Ethernet frame is the broadcast IP address as a result of the judgment, performing a virtual interface-based layer-3 broadcast routing function. 
 
     
     
       7. The method of  claim 4 , wherein performing the VLAN-based layer-2 multicast switching function comprises:
 when the destination MAC address of the received Ethernet frame is the multicast MAC address, judging whether the destination MAC address of the received Ethernet frame is a broadcast MAC address; and 
 when the destination MAC address of the received Ethernet frame is not the broadcast MAC address as a result of the judgment, copying the same packet to perform a VLAN-based layer-2 multicast switching function. 
 
     
     
       8. The method of  claim 4 , wherein performing the VLAN-based layer-2 multicast switching function comprises:
 when the destination MAC address of the received Ethernet frame is the multicast MAC address, judging whether the destination MAC address of the received Ethernet frame is a broadcast MAC address; 
 when the destination MAC address of the received Ethernet frame is not the broadcast MAC address as a result of the judgment, judging whether the destination MAC address of the received Ethernet frame is an MAC address of a well-known multicast IP; and 
 when the destination MAC address of the received Ethernet frame is the MAC address of a well-known multicast IP as a result of the judgment, delivering the packet to an upper-layer processor to process the packet. 
 
     
     
       9. The method of  claim 4 , wherein performing the VLAN-based layer-2 multicast switching function comprises, when the destination MAC address of the received Ethernet frame is not the multicast MAC address, performing a VLAN-based layer-2 unicast switching function. 
     
     
       10. The method of  claim 4 , further comprising, before performing the VLAN-based layer-2 multicast switching function:
 judging whether the destination MAC address of the received Ethernet frame is an MAC address of a virtual interface; and 
 when the destination MAC address of the received Ethernet frame is the MAC address of the virtual interface, performing a virtual interface-based layer-3 unicast routing function. 
 
     
     
       11. The method of  claim 4 , further comprising, before performing the VLAN-based layer-2 multicast switching function:
 judging whether the destination MAC address of the received Ethernet frame is an MAC address of a BPDU; and 
 when the destination MAC address of the received Ethernet frame is the MAC address of the BPDU, delivering the packet to an upper-layer processor to process the packet. 
 
     
     
       12. The method of  claim 4 , further comprising, before performing the VLAN-based layer-2 multicast switching function:
 judging whether the received Ethernet frame is an ARP (Address Resolution Protocol) packet; 
 when the received Ethernet frame is the ARP packet as a result of the judgment, copying the packet to deliver the packet to an upper-layer processor; and 
 ARP-processing the delivered packet. 
 
     
     
       13. The method of  claim 12 , wherein judging whether the received Ethernet frame is the ARP packet comprises exploring type and length fields of the received packet.